Unidirectional driving gear



Oct. 9, 1956 A. GODAT 2,765,679

UNIDIRECTIONAL DRIVING GEAR Filed-Feb. 18, 1952 s Sheets-Sheet 1 A.GODAT UNIDIRECTIONAL DRIVING GEAR Oct. 9, 1956 3 Sheets-Sneet 2 FiledFeb. 18, 1952 Nam Oct. 9, 1956 A. .GODAT 2,

UNIDIRECTIONAL DRIVING GEAR Filed Feb. 18, 1952 3 Sheets-Sheet 5 II MINVENTOR Abcl ebdar BY KMM ATTORNEY United States Patent UNIDIRECTION ALDRIVING GEAR Abel Godat, Bienne, Switzerland, assignor to Bulova WatchCompany Inc., New York, Bienne Branch, Bienne, Switzerland, ajoint-stock company of Swiss law Application February 18, 1952, SerialNo. 272,139

Claims priority, application Switzerland February 28, 1951 2 Claims.(Cl. 74-812) This invention relates to unidirectional driving mechanismadapted for use for instance in watches and other clockwork mechanisms.It will be described hereinafter as being applied to a self-windingwatch comprising in combination with an oscillating weight a pair ofintermeshing wheels pivoted on a loosely rockable yoke and in which thefirst of the two wheels is constantly in gear with a third wheel carriedalong by the oscillatory weight, while a winding wheel is arranged nearthe pair of wheels mentioned in the first place in such a manner that bythe rocking movements of the body supporting this pair of wheels, theyalternately come into operative contact with the winding wheel.

The mechanism according to the present invention is characterizedthereby that the rocking movement is provoked on the one part by a clickor pawl which coacts with the winding wheel, and on the other part by acarrier fixed to the yoke and ending in a tooth which lightly enters thegaps between the teeth of said third wheel, Whenever the yoke occupies aneutral position, i. e. a position in which none of the wheels of thepair of wheels is in mesh with the winding wheel.

The carrier may consist of a plate supported on the pivots of the pairof Wheels, but it may also be integral with the yoke.

In the drawings afiixed to this specification and formiug part thereoftwo embodiments of this invention are illustrated diagrammatically byWay of example.

In the drawing:

Fig. 1 is a plan view of the first embodiment.

Fig. 2 is a section along the line III1 in Fig. 1.

Fig. 3 is a plan view of the second embodiment showing only those partsof the mechanism represented in Fig. 1, which differ therefrom.

Fig. 4 is a section along the line IV-IV in Fig. 3, and

Fig. 5 is a section along the line V-V in Fig. 3.

In the drawing only those parts are shown which are necessary for thecomprehension of the nature of this invention.

Referring to the drawing, 1 and 2 are two wheels of similar diameterwhich are in mesh with each other and are pivoted on a yoke 3 carrying apivot 4, disposed at equal distance from the axles 5 and 6 of the twowheels 1 and 2, and by means of which the yoke is freely mountedrotatably on the bridge 10. The wheels 1 and 2 extend in the same planeand the axle 4 of the yoke 3 is parallel to the axles 5 and 6.

The wheel 1 is constantly in mesh with a wheel 7 driven by theoscillating weight 8. A winding wheel 9 is arranged near the pair ofwheels 1 and 2 in such manner that by the rocking movement of theelement 3 which supports them, they come into mesh alternately with thewinding wheel 9.

At 10 the automatic frame-work and at 11 the bridge for the automaticdevice are shown, the frame-work 10 carrying the yoke 3 while thewinding wheel 9 is pivoted in the frame-work 10 and the bridge 11.

Patented Oct. 9, 1956 The carrier consists of a plate 12 formed with twoperforations through which extend the axles 5 and 6 of the wheels 1 and2. The plate 12 rests on the wheels 1 and 2 and is axially held in placeby the automatic bridge 11. The plate 12 ends in a tooth 13 whichloosely penetrates into a gap between two teeth of the Wheel 7 when theyoke occupies a neutral position, i. e. a position in which none of thetwo wheels 1 and 2 is in engagement with the winding wheel 9. Fig. 1shows such a neutral position in full lines, while dohand-dash linesshow the position in which the wheel 1 is in engagement with the wheel9.

Assuming that the oscillating weight 8 starts turning from the positionshown in Fig. 1 in clockwise direction indicated by the arrow A, thecarrier 12 whose tooth is acted upon by the wheel 7, turns the yoke 3about its axis 4 in counter-clockwise direction and thereby brings thewheel 1 into engagement with the winding wheel 9. The movement of theyoke 3 is limited by the fact that the axle 6 of the wheel 2 extendsinto an aperture 14 provided in the bridge 11 so that a correct depth ofengagement of the wheel 1 in the wheel 9 is obtained, at which existsthe minimal relative spacing of the axes of the two wheels. If theseaxes were to further approach each other, the teeth of the two wheelswould deeply penetrate each other and would become blocked, which mustof course be avoided. If the yoke 3 occupies the correct position, thetooth 13 of the carrier 12 is out of reach of the teeth of the wheel 7.The yoke 3 is maintained in the correct extreme position by theengagement of the teeth of the wheel 1 with those of the wheel 9.

When the oscillating weight 8 starts turning in the counter-clockwisedirection, while the parts occupy the position shown in dot-and-dashlines, the wheel 1 owing to the pawl 15 cannot turn the wheel 9 incounter-clockwise direction and the teeeth of the wheel 9 force the yoke3 into a neutral position. The tooth 13 of the carrier then engages theteeth of the wheel 7 and the yoke 3 is thus carried along into its otherextreme position in which the wheel 2 is in mesh with the winding wheel.

The carrier might be integral with the yoke 3, as the second embodimentshows in Figs. 3, 4 and 5. In this case there are provided also a wheel7 actuated by the oscillating weight, two wheels 1 and 2 pivoted on ayoke 3a, and a winding wheel 9, the axes of which are arranged in thesame way as in the first embodiment.

Instead of a yoke 3 and a carrier 12 with a tooth 13, there is only ayoke 3a which is located within a shallow recess 16 provided in theupper surface of bridge 10, so that the yoke 3a lies substantially onthe same level as wheel 7.

This yoke is provided at its periphery with a tooth 13a which is madeintegral with the yoke. This tooth operates like that of the carrier 12of the first embodiment, so that the carrier may be dispensed with here.In this second embodiment, bridge 11 also holds the wheels 1 and 2axially in place.

I wish it to be understood that I do not desire to be limited to thedetails shown in the drawing and described in the foregoingspecification for obvious modifications will occur to a person skilledin the art.

I claim:

1. Unidirectional driving gear comprising in combination a drivingwheel, a loosely rockable yoke, 21 pair of wheels in engagement witheach other mounted for rotation on said yoke, one wheel of said pair ofwheels permanently meshing with said driving wheel, a driven wheelmounted so near to said pair of wheels that the wheels of said pair arecarried alternately by the rocking movements of said yoke intoengagement with said driven wheel, a pawl arranged for coaction withsaid driven wheel and a carrier operatively carried by said yoke andformed at its end with a tooth extending loosely into a gap between theteeth of said driving wheel when said yoke occupies a position in whichnone of the two wheels of said pair of wheels is in engagement with saiddriven wheel, cooperating in causing rocking movement of said yoke.

2. The mechanism of claim 1, in which the carrier is a plate mounted onthe pivots of the pair of wheels.

References Cited in the file of this patent FOREIGN PATENTS SwitzerlandNov. 16, 1944

